Detachable blade bit



Oct. 28, 1952 H. .1. HAWTHORNE DETACHABLEI BLADE BIT Filed Aug. 24, 1945n u I I I I I I I 'H.IHAWTHORNE IN V EN TOR.

Patented Oct. 28, 1952 j 1' v 2,615,684 unionism BLADE BIT Herbert J.Hawthorne, Houston, Tex.

Application August 24, 1945, Serial No. 612,416

3 Claims.

The invention relates to a detachable blade bit generally known in thewell drilling art asa drag bit. With drag bit construction the bladeportions wear rapidly by abrasion against the earth formations and it isdesirable to replace the blades while retaining or salvaging the bodyand other portions of the bit. Great difficulty is encountered, however,in securely aflixing the blades to the bit body so as to avoid looseningof the blades due to the chattering of the bit.

It is not uncommonto conduct the drilling operation in the rotary methodof drilling wells by applying weights approximately te n, twenty or eventhirty thousandpounds to the drill bit by lowering the weight of thedrill stem or operating pipe onto the bit. yWhen it is considered thatthe bit may be rotated at fifty to one hundred revolutions per minutewhile having a tremendous weight of this sort applied to it, it seemsobvious that the bit is chattering against the formation. This chatteraction tends to loosen all previous types of detachable blade bits withwhich I am familiar, and the present invention therefore contemplates aparticular arrangement of the structure whereby the blades are securelywedged in position and retained against loosening while under use underthe most exacting conditions.

It is therefore one of the objects of the invention to provide adetachable blade bit assembly wherein a plurality of blades are appliedto a body structure retained in position with a wedge member and thewedge member in turn wedged against the blade by a retainer collar.

It is one of the objects of the invention to provide wedge members whichproject outwardly from the bit body so as to be wedged in position by aretainer collar.

Other and further objects of the invention will be readily apparent whenthe following description is considered in connection with theaccompanying drawing wherein:

Fig. 1 is a side elevation of a bit constructed in accordance with theinvention and showing certain of the parts in sections.

Fig. 2 is a bottom plan view looking up at the bottom of the bit of Fig.1.

Fig. 3 is a side elevation with certain parts in the wedge memberpositioned there-against.

Fig. 4 is a bottom plan view of the bit body illustrating one of theblades in position and with section of the bit body.

Fig. 5 is a side elevation of one of the blade members.

The drill collar 3 on the lower end of the drill stem or operating pipeis shown in section as-in Fig. 1 as being internally threaded at 4 witha coarse or acme thread. The bit body 5 has a come plementary crossthread 6 thereon to be threaded in engagement with the thread 4. Toprovide. a seal and protect the thread 4 and 6 against cor-. rosion andbecoming wedged by sediment and foreign matter, a bushing I is threadedinto the upper end of the bit body and carries a resilient v ring 8which flares outwardly against the wall 9 of the passage through thedrill collar.

The bit body 5 has a central passage l0 therein for the flow of drillingmud or flushing fluid through the bit.

The bit body is of peculiar construction as seen in Figs. 3 and 4 inthat it has the upper cylindrical portion II which flares outwardly at[2 to form a tapered peripheral face. This face, however, is cut away toprovide the enlarged notches l4. There may be any desired number ofthese notches because bits of this type are usually known as two, threeor four-way bits. depending upon the number of blades provided. The bitillustrated in the drawing is a three-way bit and there are thereforethree of these notches M as best seen in Fig. 4. Each of these notchesis formed by a substantial right angle I5 adjacent the center portion ofthebit so as to provide the outstanding flanges I6,1three of which areseen in Fig. 4. 1

The flanges 16 have a surface 20 against which the blade 21 is adaptedto be positioned as best seen in Fig. 4. To properly position the blade,a lug 22 is formed in each of the notches l4 and arranged to have therecess 24 in the blade fitted thereover. the lug properly positions theblade and prevents it from dropping out of the body.'

To retain the blade and clampit in position a geometrical solid wedgemember 30 ispositioned in each of the notches l4 and arranged to abutthe blade 2| as best seen in Fig. 4. This wedge member will be cut awayto accommodate the lug 22 and is thus arranged to abut the rear edge 3|of the blade and the forward edge 32 of the notch. Particular attentionis called to the fact that the curved surface 33 of this wedge member isnot an arc of a true circle but radially flares outwardly somewhat sothat the rear heel portion 34 projects beyond the periphery 35 of theflange Hi. This projection is also seen in Fig. 1. In this manner thewedge member projects beyond the tapered face l2 of the bit body and isarranged to be engaged by the clamping collar 40 which has the internali'rusto-conical best i This interfitting of the recess and 3 face 4| asseen in Fig. 1. This collar is of substantial length and its lower end42 extends over the wedge member 30 almost to the base 44 thereof.

The upper end of the collar at 45 is arranged to abut against the lowerend 45 of the drill collar 3.

In assembling the bit the blades 2| will be placed in position with therecesses 24 over the lugs 22. The wedge members 30 will then bepositioned and the bit body, blades and wedges will have the collar 40dropped thereover so as to hold the parts assembled. The drill collar isthen threaded into position by engaging the threads 4 with the threads 6and this threading action tends to wedge the collar 40 securely over theblades and wedge members 30 so that the wedging action clamps the bladesin position. The construction just described results in-a continuoustightening action on the threaded area because the torque applied to thedrill stem in rotating the bit tends to make the threads uptighter. Thehammer eiTect or chattering of the bit against and due to the cutting ofthe formation causes the parts to gradually fit together more closelyand this continuous backing up of the bit due to the friction of theblades against the formation insures against loosening of the parts. Inactual operation, the bits constructed in accordance with the inventionhave given exceptional service.

The blade member is shown as having the cutting edge 50 adjacent itscenter and the outwardly extending cutting area with the gauge cuttingedge 52 in a vertical position.

In order to conduct the mud or flushing fluid from the passage II] aplurality of water courses 53 which terminate in the discharge ports 54in the lower end of the bit body have been illustrated. One of thesewater courses is directly in front of each of the blades.

Broadly, the invention contemplates a detachable blade bit where theblades are secured bya wedging action in position upon the bit body by aclamping collar. In this manner the direct thrust of the rotative forceof the drill stem and drill collar against the clamping collar istransmitted to the blades and bit body by the clamping collar so that arigid securing means is provided.

What is claimed is:

1. A detachable blade bit comprising a body for rotation by a drillstem, a blade supporting area thereon, radial notches in said bodyforming a portion of said area, means disposed in each notch including ablade portion, an internally tapered clamping collar to slidably fitover said body and means, and a driving drill collar threaded onto saidbody to abut the top of said clamping collar so that the resistance toturning or the blades against the formation causes the rotation of thedrill stem to continuously urge said driving drill collar to force saidclamping collar downwardly along said body to exert a wedging actionupon said means and interfitting portions on said blades and body toretain said blades on said body against longitudinal thrust in spite ofsuch driving action.

,2. A detachable blade bit comprising a body for rotation'by a drillstem, a blade supporting area thereon, drag bit blades contacting saidblade supporting area, means on said blade supporting area and saidblades to retain said blades on said body against rotational movement,an internally tapered clamping collar to slidably fit over said body andsaid blades, and a driving drill collar threaded onto said body to abutthe top of said clamping collar so that the resistance to turning of theblades against the formation causes the rotation of the drill stem tocontinuously-urge saiddriving. drill collar to force said clamping.collar downwardly along said body to exert a. wedging action upon saidblades, and interfitting. portions on said blades and body to retainsaid blades on said body against longitudinal thrust in spite of suchdriving action.

3. A detachable blade bit comprising a body for rotation by a drillstem, a plurality of blade supporting areas thereon, drag bit bladescontacting said blade supporting areas, inter-em gaging means on saidblade supporting areas and said blades to retain said blades on saidbody against longitudinal thrust and rotational and turning movementswith respect to said body, an internally tapered clamping collar toslidably fit over said body and said blades, and a driving drill collarthreaded onto said body above the top of said clamping collar so thatthe resistance to turning of the blades against the formation causestherotation of the drill stem to continuously urge said driving drillcollar to force said clamping collar downwardly along said body to exertawedging action upon said means.

HERBERT J. HAWTHORNE.

REFERENCES CITED The following referencesare of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,290,412 Trakimas Jan. '7, 19191,774,084 Cooney Aug. 26, 1930 1,861,928 Loeifelman June 7, 19322,199,692 Catland May 7, 1940 FOREIGN PATENTS Number Country Date105,606 Germany Oct. 5, 1899

